Jason Collins will be the answer to many trivia questions for decades to come. Tonight, he became the first openly gay athlete to play in any of the four major U.S. pro leagues. The likes of John Amaechi and Robbie Rogers have helped pave the way for this moment to finally happen. There’s also been countless straight allies who took up the cause of ensuring we, as a society, challenge the way we view sport, sexuality, and masculinity.Michael Sam will soon follow in Collins’ footsteps, and then many more. Tonight was a historic and crucial first step to realizing a more inclusive society. Also, check out Dave Zirin’s thoughts over at The Nation.Watch below as Collins enters the Lakers-Nets game.